Liquid-delivery apparatus



Aug. 14, 1928.

J. J. HAWXHURST LIQUID DELIVERY APPARATUS Filed' Fb. 23,- 1927' Patented Aug. 14, 1928.

- UNITED STATES PATENT OFF-ICE.

JOHN J. HAWXHUR-ST, OF BROOKLYN, NEW YORK, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO LIQUID DISPENSING SYSTEMS, INC., 01 BROOKLYN, NEW YORK,

A CORPORATION OF NEW YORK.

LIQUID-DELIVERY APPARATUS.

Application filed February 23, 1927. Serial No. 170,196.

rhis invention relates particularly, though not exclusively, to gasoline delivery systems of the type disclosed in my copending Patent 1,618,006, wherein the liquid is trans ferred from a storage tank into a delivery tank in such a way as to create and maintain an air cushion under proper pressure to cooperate in the delivery of liquid. It has been found that there is a tendency for this air cushion to build up, by leakage of air into the system through the stufiing boxes of the pump which transfers the liquid from the storage tank to the delivery tank, etc.

Special objects of the present invention are to control this air cushion and particularly to prevent it from lowering the liquid in the delivery tank to such a point that air may pass out through the delivery line and thus cause false readings of the delivery meters.

Other important objects and the novelfeatures ofthe invention by which all are attained will be apparent from the following specification.

The drawings accompanying and forming part of this specification illustrate one of the practical commercial embodiments of the invention,,but it will be understood that the structure is capable of modification and jchange in various respects without departure *from the intended and true scope of the invention as hereinafter defined and broadly claimed.

Figure 1 is a partly diagrammatic illustration of a complete liquid delivery system having the invention incorporated therein.

Figure 2 is a broken enlarged view of the air cushion control connections and related parts.

Figure 3 1s a fragmentary outline of amodified form of the invention.

In Figure 1 the storage tanks are shown at 3 and the delivery or pressure tank is indicated at 1, disposed at a higher level than the lowest level of the storage tanks. This delivery tank, in practical installations, has been of about sixtygallons capacity so as to hold when half full about thirty gallons of liquid with a large bodyof cushioning air actingon the same. 7

The transfer of liquid from the storage tanks to the delivery tank is effected in the present disclosure by a liquid pump 5 connected 1n a transfer line 6 running from the storage tanks to the lower portion of the del1very tank. This liquid pump is indicated as driven by an electric motor 7 controlled by a pressure actuated switch 8 which derlves its control pressure from a by-pass connection 9 taken off from the transfer line or otherwise connected with the pressure tank. A check valve 10 interposed at some point 1n the transfer line prevents back flow through this line.

The delivery line indicated at 11 is shown as extending from the bottom portion of the delivery tank so as to carry off solid liquid to the delivery stand or stands, two of these being shown at 12 supplied by branches 13 from the delivery line 11.

From the description thus far it will be apparent that the pump will operate to transfer liquid from'the storage tanks into the lower portion of the delivery tank with the result that the air cushion will build up in said delivery tank on top of the liquid therein. This transfer will continue until the pressure in the delivery tank is brought up to the point for which the automatic switch is set and any time the pressure in the delivery tank is lowered below such point, for instance, by discharge of liquid at the delivery stands, the pump will be automatically cut into operation to recharge the de livery tank with liquid and restore the desired pressure therein.

For best operations, thus far, it has been found that the air cushion should not ex- 1 livery tank there is provided in the present invent-ion a control line 14 in communication with the contents of the delivery tank at a point substantially corresponding with the level which it is desired to maintain.

Thus in the illustration this ontrol line enters the delivery tank at substantially the indicated at 16. In order that the flow.

through this return line niay be observed, a suitable sight glass may be interposed therein as indicated at 17..

It will be seen that by operating valve 15 to open up the return line 14, 16, air in,

the delivery tank, if it has accumulated sufficiently to lower the liquid below the half way mark, will be vented and that as soon as liquid commences to flow, following on the reduction of the air cushion, such liquid will simply be passed back into the storage tanks The sight glass in the return line will show when the liquid flow commences and enable the operator to gauge his actions accordingly.

If it is desired to test the action of the pump, the valve 15 may be left open for some time, the liquid being transferred to the delivery tank being then simply returned back to the storage tank. In this way by means of valve 15, the pump may be caused to operate either continuously, or if desired, in an intermittent fashion and in such a way as to test the action of the pressure control switch and other parts of the automatic liquid transfer mechanism.

-To prevent an accumulation of pressure within the delivery tank which might become injurious or dangerous, an automatic pressure relief valve is shown at 18 controlling a line 19 extending back to the nearest storage tank. This automatic pressure relief device communicates with the contents of the delivery tank by a connection 20 extending to below the normal or desired liquid level therein so that in operating under conditions of excessive pressure, it will simply return liquid back to the storage tank and will not reduce the air cushion therein. This excess pressure control means, therefore, does not interfere with the maintenance of the, desired air cushion and liquid level in the pressure delivery tank.

The pressure tank has a deairing function, allowing air which has been entrained with the liquid by the action of the pump in transferring liquid from the storage tank to the delivery tank, to rise and be absorbed by the air cushion. The pressure tank therefore aids in insuring delivery of solid or deaired liquid through the delivery line.

This deairing action has a tendency to create an'over-abundance of air in the air cushion,

but this can be counteracted at any time. by

use of the vent line 14, 16. Also, the vent line may be opened any time it may become desirable to reduce pressure in the pressure tank, for instance, at a time when it ma be desirable to take some of the pressure 0 the liquid therein to enable the liquid to more readily give up any air that may be entrained therein.

It will be noted that an air cushion will be retained in the pressure tank despite the opening of the vent line because this vent line will draw off air only so lon as the air cushion extends below the hal -way level in the tank. As soon as the liquid level rises above the point where the vent line is connected in the tank, further esca e of air will be prevented. This is particu arly true because of the fact that all other lines entering this tank extend down toward the bottom of the tank and communicate with the contents of the tank below the level of the venting connection.

To simplify the piping, the vent line may be connected in the excess pressure return line 19, 20 in the form of a by-pass about the automatic pressure relief valve 18, as indicated at 14, 16, Figure 3. In this case the entrance to the return line is the factor which establishes the liquid level and hence the depth of air cushion in the tank, so the pipe 20 is entered into the tank to about the half-way level therein, as indicated at 21.

What is claimed is:

1. In liquid delivery apparatus, a storage tank, adehvery tank, means for transferring liquid from said storage tank to said delivery tank, a delivery line taking liquid from the lower portion of said delivery tank, means for controlling the transfer of liquid to maintain a cushion of com ressed air acting on the liquid in the delivery tank and means for venting excess air in the topof the delivery tank to prevent said air cushion from lowering the liquid in the delivery tank below a desired minimum level.

2. In liquid delivery apparatus, a storage tank, a delivery tank, means for transferring liquid from said storage tank to said delivery tank, a delivery line taking liquid from the lower portion of said delive tank means for contro the transfer 0 liquid to maintain a cushion of compressed air acting on the liquid in the delivery tank and means for venting excess air in the top of the delivery tank to prevent said air cushion from lowerin the liquid in the delive tank below a desired minimum level, inclu ing an air relief line communicating with the ileliyery tank at about said desired minimum eve 3. In 1i uid delivery apparatus, a store e tank, a delivery tank, means for transferri g liquid from said storage tank to said delivery tank, a delivery line taking liquid from the lower portion of said delivery tank means for controlling the transfer of liquid to maintain a cushion of compressed air acting on the liquid in the delivery tank and means for venting excess air in the to of the delivery tank to prevent said air cus ion from lowering the liquid in the delivery tank below a desired minimum level, including an air relief line communicatin with the delivery tank at about said desired minimum level, said air relief line having valving means and means for observing flow through the same.

4. In liquid delivery apparatus, a storage tank, a delivery tank, means for transferring liquid from said storage tank to said delivery tank, a delivery line taking liquid from the lower portion of said delivery tank, means for controlling the transfer of liquid to maintain a cushion of compressed air acting on the liquid in the delivery tank and means for venting excess air in the top of the delivery tank to prevent said air cushion from lowering the liquid in the delivery tank below a desired minimum level, including a return line extending from said desired minimum level in the delivery tank back to the storage tank.

5. In liquid delivery apparatus, a storage tank, a .delivery tank, means for transferring liquid from said storage tank to said delivery tank, a delivery line taking liquid from the lower portion of said delivery tank, means for controlling the transfer of liquid to maintain a cushion of compressed air acting on the liquid in the delivery tank and means for venting excess air in the top of the delivery tank to prevent said air cushion from lowering the liquid in the delivery tank below a desired minimum level, including a return line extending from said desired minimum level in the delivery tank back to the storage tank and having valve mechanism therein.

6. In liquid delivery apparatus, a delivery tank, a delivery line taking liquid therefrom, means for creating an air cushion acting on the liquid in said tank and means operative to prevent said air cushion from lowering the liquid in the tank below a desired minimum level.

7. In aliquid delivery apparatus, a delivery tank, a delivery line taking liquid therefrom, means for creating an air cushion P I tank, a delivery line taking liquid therefrom,

means for creating an air cushion acting on the liquid in sald tank, means operat ve to prevent said air cushion from lowering lief device connected with said tank, at a point below said desired minimum level.

10. In liquid deliveryapparatus, a delivery tank, a delivery line taking liquid therefrom, means for creating an air cushion acting on the liquid in said tank, a relief line in communication with the contents of said tank at a point substantially corresponding with a desired minimum liquid level therein, valve mechanism for ,controlling flow through said relief line and means for enabling observation of the character of flow through said relief line.

11. In liquid delivery apparatus, a delivery tank, a delivery line taking liquid therefrom, means for creating an air cushion acting on the liquid in said tank, means operative to prevent said air cushion ,from lowering the liquid in the tank below a desired minimum level, including a relief line communicating with the tank at the desired minimum level and having valve mechanism controlling flow therethrough and a maximum'pressure relief device in communication with the contents of the tank at a point below said desired minimum level.

12. In liquid delivery apparatus, a pressure tank, a vent line communicating with the interior of said tank at a point above the lowest level therein, a delivery line communicating with the contents of the tank at a point below the vent connection and a supply line communicating with the contents of the tank also below the level of said vent connection.

13. In liquid delivery apparatus, a pres" sure tank, a vent line communicating with the interior of said tank at a point above the lowest level therein, a delivery line communicating with the contents of the tank at a point below the vent connection, a suply line communicating with the contents of the tank also below the level of said vent connection and a pressure relief connection communicating with the contents of the tank below the level of said vent connection.

14. In liquid delivery apparatus, a detherefrom, means for creating an air'cushion acting on the liquid in said tank, means for preventing said air cushion from lowering the liquid in the tank. below a desired minimum level and a maximum pressure relief.

. livery tank, a delivery line taking liquid device connected with said tank, said pretherein, said return line being! open to the 10 venting means comprising a venting by-pass interior of the tank substantially at the level about the maximum pressure relief device. of desired maximum air cushion therein and 15. In liquid delivery apparatus, a dea controllable venting by-pass about the 5 livery a delivery line taking liquid pressure relief device in the return line.

therefrom, means for creating an air cushion In witness whereof, I have hereunto set acting on the liquid in said tank. a return my hand this 12th day of January, 1927.

line extending from said tank and having a. maximum pressure relief device interposed JOHN J. HAWXHURST. 

